13.05.16
Bryn yr Ŵyn (SN 839 925), Bryn Llwyd (SN 835 920) and Fedw Ddu
(SN 856 917)
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| Bryn Llwyd (SN 835 920) centre left of photo and Bryn yr Ŵyn (SN 839 925) on right of photo |
Having visited Bryn Llwyd (this is a locally known name, used in preference to Esgair
Greolen which appears on Ordnance Survey maps) and Bryn yr Ŵyn eight days ago the resulting data for each summit and the
drop attained for the higher of the two was of sufficient interest that a
second survey was warranted.
I approached from the
south-east from where a minor road heads south from the small community of Penffordd
Las (Staylittle). A passing place proved
convenient to park with a few other such places also available near to where a
track heads north toward the farm of Nant-yr-hafod.
The forecast for the day
was good with sunshine and dry conditions predicted and as I walked up the
track the morning’s blue sky pieced the landscape. Just before the farm the track veers west
toward the 488m map heighted summit of Fedw Ddu, and it was here that I met Gareth
Griffith who came chugging around the bend with three farm dogs scampering
around his vehicle. I waved a ‘hello’ as
I lifted the catch on a gate and he pulled up for a chat.
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| Gareth Griffith |
Gareth had lived at
Nant-yr-hafod for forty years and was heading up the hill to feed the sheep. I explained where I was hoping to go and as
some of this land was not a part of open access or did not have a right of way
on it, I asked if he minded me using the continuation of the track, he was
happy enough for me to do this and we continued our conversation, he told me that
he still goes out shepherding on horseback and soon the topic of hill names was
mentioned. He proved extremely
knowledgeable and rolled off name after name of the hills and streams above
where he farmed. One name in particular
was of interest, it related to the hill that Ordnance Survey maps name as
Esgair Greolen, which is the hill I wanted to concentrate the morning’s
surveying activities on. He knew this
hill by a different name; Bryn Llwyd, and after mentioning it he said that ‘this name
doesn’t appear on the map.’
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| Gareth and his dogs |
As Gareth was heading up
to the end of the track which is close to the summit of Fedw Ddu I asked if I
could have a lift, he kindly said yes and within a couple of minutes I was
happily sitting next to him in his vehicle as it chugged its way up the track. He stopped three times to unload sheep feed
and put his dogs in the cage on the trailer at the back. Rarely do you have an opportunity to make
such swift progress up a hill, and as he pulled up at the end of the track I
clambered out, put my rucksack on, shook his hand and thanked him in Welsh.
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| Time to feed the sheep |
As Gareth turned his
vehicle round I waved my thanks and he disappeared down the hill, leaving me in
the early morning sunshine smiling at the thought of how little energy I’d used
to get so high. Within a few minutes I
was assessing the land at the bwlch of Fedw Ddu and soon had the Trimble
positioned on my rucksack gathering data.
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| Gathering data at the critical bwlch of Fedw Ddu |
Beyond this bwlch a path
on the open hillside made good progress toward the summit of Bryn yr Ŵyn. I planned to take a further two data sets
from this first summit, giving five in all when combined with my previous
visit, I also wanted to take three data sets from the summit of Bryn Llwyd which would make four in all when combined with those previously taken, and at
least seven data sets from the area of the critical bwlch. All accumulated summit data could be averaged
to give the absolute height of each hill, whilst the bwlch data would give an
evaluation of the lay of land on the hill to hill traverse, when the data were
combined the higher summit would be clarified and its drop obtained.
Once on top of Bryn yr Ŵyn
I quickly placed the Trimble on the same point as I had eight days previously
and stood a safe distant from it and below it as the first of what proved to be
a further 19 data sets were gathered from these hills. Away to my south south-west Bryn Llwyd looked distinctly lower, as it does from almost every angle that I’ve viewed
these hills from.
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| Gathering data at the summit of Bryn yr Ŵyn |
Once a further two data
sets were gathered from the summit of Bryn yr Ŵyn I walked over the
moor toward Bryn Llwyd and took a further three data sets from its
summit. I placed the Trimble on the
ground for two of these data sets and once on top of my rucksack.
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| Gathering data at the summit of Bryn Llwyd |
All that remained was to
gather data from the bwlch, this proved fun as a further 13 data sets were
taken. The first of which was from where
contour interpolation suggests the critical bwlch to be placed on the ground,
I’d taken the third bwlch data set from this position on my last visit and
judged this to be visually on the downward slope of the valley to valley
traverse, with the traverse from the hill to hill direction just a few metres
to the north of this point.
During the remainder of
my time at the bwlch I took 12 data sets on what I judged to be on the hill to
hill traverse, this heads in a west to east direction. On every bwlch data set I positioned the
Trimble atop my rucksack to give it elevation above the surrounding moor and
measured the offset between its internal antenna and the ground with a steel
tape. The furthest point from where I
gathered bwlch data from to the west and to the east was at a point that was
visually on the upward slope of the hill to hill traverse, with the remainder
of the positions approximately 8-10 metres apart, and on the land that I judged
to be where the low point of the hill to hill traverse was situated I took data
sets five metres apart. Each point was
marked with a flag which proved ideal to visually assess the lay of land. Once all data sets were complete I packed
everything away and started the walk back toward my car.
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| The march of flags across the bwlch |
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| The positions surveyed at the bwlch are indicated with flags with Bryn Llwyd in the background |
Leaving the bwlch I
followed a path which crests the connecting bwlch between Bryn Llwyd and Bryn
yr Ŵyn and contours around the latter’s southern slopes before
joining the inward path and track toward Fedw Ddu. I’d visited this hill once before and
wondered if summit data were possible to collect as its high point is immersed
in a conifer plantation.
A forest break
conveniently passes over where the spot height appears on the map, and I
followed the moss laden ground between the trees until the up seemed to have
ended and the beyond seemed to consist of down.
I aimed for a high point at the base of trees and happy that I’d visited
what could be construed as the summit I positioned the Trimble to try and
collect data, remarkably its 0.1m accuracy level before data should be logged
was attained relatively quickly, and as it beeped away collecting its customary
300 data points I stood behind one of many conifer trees, out of sight of the
equipment.
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| Gathering data at the summit of Fedw Ddu |
After packing the
Trimble away all that remained was to re-trace my inward route, this time on
foot, and 6 ½ hours after setting off I arrived back at my car
with 19 data points stored in the Trimble.
Survey Result:
The result of the processed
data for the first Trimble survey of Bryn Llwyd and Bryn yr Ŵyn was of sufficient interest to warrant
another survey, and therefore the following detail takes in the combined
results from each survey:
Bryn yr Ŵyn
Summit Height: 499.9m (converted to OSGM15, and average of five surveys and summit relocated to Bryn Llwyd [SN 83574 92022])
Summit Grid Reference: SN 83919 92571
Drop: 9.9m
Dominance: 1.99%
Bryn Llwyd (significant name change)
Summit Height: 501.4m (converted to OSGM15, and average of four surveys and Dewey and Uchaf
status confirmed and summit relocated from Bryn yr Ŵyn [SN 83919 92571] and new Pellennig hill qualifying on distance)
Summit Grid Reference: SN 83574 92022
Bwlch Height: 471.2m (converted to OSGM15)
Bwlch Grid Reference: SN 83220 91901
Drop: 30.3m (500m Twmpau status remains)
Dominance: 6.04%
Fedw Ddu
Summit Height: 487.7m (converted to OSGM15)
Summit Grid Reference: SN 85672 91803
Bwlch Height: 434.8m (converted to OSGM15)
Bwlch Grid Reference: SN 85176 91727
Drop: 52.9m
Dominance: 10.85%
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